Compressor



Aug. 28, 1956 Filed June 30, 1952 H. J. WOOD COMPRESSOR 3 Sheeis-Sheet l jio'mse 71 500,

INVENTOR.

ArraeMs-K Aug. 28, 1956 H. J. WOOD 2,760,719

COMPRESSOR Filed June 30, 1952 3 Sheets-Sheet 2 g- 23, 1955 H. J. WOOD 2,760,719

COMPRESSOR Filed June 30, 1952 r 5 Sheets-Sheet 3 INVENTOR.

COMPRESSOR Homer J. Wood, Sherman Oaks, Calif; assignor to The Garrett Corporation, Los Angeles, Calif., a corporation of California Application June 30, 1952, Serial No. 296,361

2 Claims. (Cl. 230-128) The present invention relates generally to. fluid compressors, and is more particularlyconcerned with a compressor of the type which will have a broad operating range.

It is one object of the herein described invention to provide a compressor having not. onlya higher through flow rate than heretofore obtainable, but alsohigher performance components.

A further object is to provide. amultistage compressor embodying backwardly curved impellers which are so arranged that a broad range of operation will'be obtained both above and below that corresponding. to peak efliciency.

A still further object is to-provide a. multistage compressor in which the first stage comprises a double impeller taking air in from opposite sides, and havingacombined discharge which is conducted to asecond stage impeller.

Another object is to provide a novel. rotor structure in a multistage compressor, wherein the respective-stage impellers are supported on a common hollowshafthaving an internal spline connection with a driving. shaft intermediate its ends.

Still another object is to provide a compressor of the herein described type havingnovel sealing, means for the various stages, and between the stages.

Further objects of the invention will. be. brought out in the folowing part of the specification,.wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon.

Referring to the accompanyingjdrawings, which are for illustrative purposes only:

Fig. 1 is an elevational view of a fluid compressor embodying the features of the-present invention;

Fig. 2 is an end view, portions of thehousing being cutaway to disclose the operative relationship of an associated diffuser and guiding vane;

Fig. 3 is a longitdinal sectional view; taken substantially on line 33 of Fig. 2;

Fig. 4 is a sectional view showing the construction of one of the cross-over ducts, and

Fig. 5 is a fragmentary sectional view of an impeller shroud seal detail, taken substantially on line 5--5 of Fig. 3.

Referring now to the drawings, for illustrative. purposes the compressor of the present invention is disclosed as comprising a housing or casing formed'by end sections A and B assembled and secured in end to-end relation with an intermediate housing section C. These sections are of substantially cylindrical construction and cooperate to house a multistage rotor construction which will subsequently be described.

Referring more specifically to Fig. 3' of the drawings, the end section A is constructed with an outer dished wall 10, and an inner wall 11' which is supported in spaced relation to the outer wall by means of a plurality of circumferentially spaced webs 12. The outer wall has a central tubular hub portion 13 which cooperates with the nited States Patent 0 spaced inner periphery of wall 11 to provide an annular fluid inlet flow passage 14 to the first stage of the compressor. At its outermost end, the passage 14 communicates through openings in the periphery of the end section A with ambient air. These openings are closed by a circumferentially extending screen 15.

The end section Bis constructed to form a scroll outlet 16 for the discharged compressor fluid, and includes an outer wall 17 having an outwardly flared projecting shell portion 18 by means of which this end section may be connected with suitable power means, such as a gas turbine. The opposite side of the scroll 16 has a circumferentially extending flange 19, and the outer periphery of Wall 11 of end section A is similarly provided with a flange 20 by which the end sections are respectively connectib'le with the adjacent ends of the intermediate section C.

The intermediate section C is a shell-like structure having one end Wall 21 which is connectible with the flange 19 of end section B, and an end wall 22 which carries at its outer periphery a flange 23 that is interconnected with flange 20 by means of suitable securing bolts 24, a difiusser ring 25 being clampingly engaged between these flanges.

Intermediate the end walls 21 and 22, the intermediate section C is provided with an intermediate wall structure 26 which is connected with the wall structure 22 by means of a plurality of circumferentially spaced webs 27 to cooperatively form at their inner peripheries an inlet fluid flow passage 28, the other end of this passage communieating with ambient air. A screen 29 is positioned over the outer end of this passage.

Likewise, the intermediate wall structure 26 is connected with and integrally formed with the end Wall 21 by means of a plurality of web structures 38 which cooperate with the Walls 21 and 26 to form a plurality of circumferentially spaced inlet openings 31 at the periphery of section C, these openings communicating with a flow passage 32 for delivery of inlet fluid to one of the compressor stages, in this instance the final stage.

Within the compressor housing composed of the sections A, B and C in assembled relation as described above, there is mounted a rotatable structure which is illustrated as comprising in this instance a hollow shaft 33 which carries a first stage impeller 34 and a second stage impeller 35. One end of the shaft 33 is rotatably supported in an anti-friction bearing 36, the inner race of the bearing being secured to the associated end of the shaft 33 by suitable means and the outer race supported from the outer wall 17 of end section B. The opposite end of the shaft 33 is supported in a bushing 37 positioned in the hub portion 13 of wall 10 of end section A.

The rotor structure of the compressor is driven from a driving shaft 38 which is arranged for connection with a power source (not shown) such as a gas turbine. This shaft extends through one end of the hollow shaft 33 and has a splined connection 39 with the interior of the shaft 33 at a point intermediate its ends. Provision is also made for driving accessories, and for this purpose a second shaft 40 is provided with a splined connection 41 with the hollow shaft, the shaft 46 extending through the other end of the hollow shaft 33 where it may be connected with and drive required accessories (not shown). This provides a torque shaft driving connection which reduces vibration and permits a certain amount of flexible accommodation of the parts of the rotor structure.

The impeller 34 of the first stage of the compressor 18 constructed with a double set of blading as indicated by the numerals 42 and 43 in back to back relation. This blading is curved opposite to the direction of rotation and arranged to have a peripheral discharge at an angle. Fluid intake is on opposite sides of the impeller through flow passages 14 and 28 respectively, and the discharge from the blading which is fully shrouded is carried from the impeller periphery through a vane ring 44 containing a plurality of vanes 45 which act to guide the impeller discharge into a plurality of substantially tangentially extending outlet ducts 46 which terminate at their outermost ends in a flanged connection 47, these connections being circumferentially spaced around the diifuserring 25.

The fluid outlet from the first stage impeller 34 is conducted to the second stage impeller 35 through crossover ducts 48, as shown in Fig. 4. These ducts have their straight portions constructed with increasing crosssection so as to act as a linear difluser, and each have an elbow end which terminates in a connection flange 49 adapted for connection with one of the connection flanges 47, and another elbow end which terminates in a connection flange 50 adapted to be connected with one of the inlet openings 31. In the elbow ends, suitable vanes 51 are provided for guidingly directing the flow of fluid through the elbow ends into the linear portions of the cross-over duct.

The fluid from the first stage is thus conducted to flow passage 32 from whence it enters the single set of blades 52 which are similarly curved opposite to the direction of rotation and arranged to discharge at their periphery at an angle, and are fully shrouded as in the case of the blading on impeller 34. The discharge-d fluid from impeller 35 is carried through a diffuser ring 53 into the scroll 16.

Sealing means are provided for the respective stages of the compressor. Between the impellers 34 and 35 there is supported from the intermediate wall structure 26, a tubular housing 54 having spaced inwardly extending flanges 55 which at their inner peripheries are in sealing relation with the adjacent periphery of the hollow shaft 33. Cooperatively associated with a portion of the flanges 55 so as to form in effect a labyrinth seal are a plurality of outwardly extending flanges 56 formed on the outer periphery of the hoilow shaft 33 and interleaved with the adjacent flanges 55.

Seals are likewise provided at the inlets of the impellers. Each seal assembly, as shown in Fig. 5, is of similar construction and comprises a ring 57 which is affixed to the outer shroud of the impeller and has a plurality of spaced circumferentially extending grooves therein which respectively cooperate with flexible bands 58 which are supported by a circumferentially extending ring bracket 59 or other suitable means form the adjacent housing structure.

At the first stage end of the compressor, the shaft 33 is provided with a nut 60 for retaining the impeller 34 on the shaft. The outer surface of this nut is grooved so as to provide a sealed engagement with a concentrically extending seal ring 61 which is adjustably supported on the bushing 37.

At the opposite end of the shaft 33, there is provided an oil slinger 62 for carrying lubrication to the antifriction bearing 36. This oil slinger is provided at its periphery with a grooved circumferentially extending surface which is in sealing relation with a stationary sealing ring 63 supported in the adjacent wall 17 at this end of the compressor.

Thus, by the utilizing of a double first stage impeller and a single second stage impeller having blading which is rearwardly curved and discharges the compressed fluid at an angle, a unique construction is obtained which results in an extremely high through-flow rate and high performance components which are not obtain-able with the conventional arrangements heretofore utilized. The impeller arrangement also permits of utilizing a housing construction in which an etfective seal may be utilized between the impeller stages and at the inlets to the impellets, and in its broad concept provides a compressor from which a broadrange of operation will be obtained both above and below that corresponding to peak efliciency.

Various modifications may suggest themselves to those skilled in the art without departing from the spirit of my invention, and hence, I do not wish to be restricted to the specific form shown or uses mentioned, except to the extent indicated in the appended claims.

I claim:

1. In a multistage fluid compressor: a first stage housing section including a plurality of substantially tangentially extending outlet ducts; a first stage double impeller rotatably supported in said housing section with discharge outlets and having separate annular inlets positioned on opposite sides of said outlet ducts; a guide ring member surrounding said double impeller and having vanes for directing fluid from said outlets to said outlet ducts; a second stage housing section axially spaced from said first housing section, and including a plurality of separate substantially radially extending inlet ducts; a second stage impeller rotatably supported in said second stage housing section with an inlet in communication with said inlet ducts; an annular fluid intake defined by said housing sections having communication with one of the double impeller inlets; cross-over ducts respectively interconnecting the outer ends of said outlet ducts and said inlet ducts, whereby fluid compressed in the first'stage is fed to spaced inlet ports of the second stage; and a protective screen member extending around said annular intake and positioned inwardly of said cross-over ducts.

2. A fluid multistage compressor, comprising: a housing; a hollow shaft inset housing; hearings in said housing respectively supporting said hollow shaft at its ends; a first stage double impeller in said housing on said hollow shaft positioned inwardly of and adjacent to the bearing at one end of the hollow shaft, and having a combined peripheral discharge; separate inlets in said housing for said double impeller respectively positioned on opposite sides of said discharge; a second stage impeller in said housing on said hollow shaft positioned inwardly of and adjacent to the bearing at the other end of said hollow shaft, and an inlet in said housing for said second stage impeller adjacent one of the inlets of said double impeller: a labyrinth seal in said housing on said hollow shaft positioned between the adjacent inlets of the double impeller and second stage impeller; a driving shaft within the hollow shaft; and a splined connection between said driving shaft and the interior of said hollow shaft, said splined connection being positioned within said labyrinth seal, whereby shaft distortion effects within the seal area are minimized.

References Cited in the file of this patent UNITED STATES PATENTS 1,097,729 Rice May 26, 1914 1,287,367 Loewenstein Dec. 10, 1918 1,324,664 Graemiger Dec. 9, 1919 1,490,219 Labberton et al Apr. 15, 1924 2,370,202 Stewart Feb. 27, 1945 2,404,334 Whittle July 16, 1946 2,414,551 Pavlecka etal Jan. 21, 1947 2,540,526 Howell Feb. 6, 1951 2,578,617 Watson Dec. 11, 1951 2,646,209 Galliot July 21, 1953 2,695,499 Waiker Nov. 30, 1954 FOREIGN PATENTS 71,244 Switzerland July 12, 1915 128,827 Australia Aug. 19, 1948 182,748 Great Britain 1923 229,267 Switzerland Jan. 17, 1944 671,427 Great Britain May 7, 1952 1,000,903 France. Oct. 17, 1951 

